1. Field of the Invention
The present invention generally relates to a blower and, more particularly, to a blower blade assembly having a plurality of blades, at least one of which is provided with a counterbalancer.
2. Description of the Prior Art
In air-conditioners, an electrically operated blower is generally utilized and includes a blower blade assembly comprising a plurality of blower blades. It has been well known and is still routine to suppress a wobbling motion of the blade assembly during the rotation thereof about an axis of rotation by equipping at least one of the blower blades with a counterbalancer at a location offset from the axis of rotation of the blower blade assembly.
The counterbalancer generally employed in the art is available in various types. One type is a generally V-shaped rigid element that is mounted on the blower blade with a side edge of the blower blade received in a V-shaped space and is then squeezed by the use of pincers or tongs. Another type is a generally rectangular rigid element that is mounted on a convex surface of the blower blade, having a sectional shape similar to that of a bow, so as to partially embrace the blade and is then fixed in position by the use of a bonding material.
Still, another type is a generally U-shaped clip-like element having a gap smaller than the thickness of the blower blade and mounted on the blower blade in a manner similar to the U-shaped rigid counterbalancer referred to above, but without using the pincers or tongs. This clip-like counterbalancer when mounted on the blower blade contacts two points on respective opposite surfaces of the blower blade.
The use of the V-shaped rigid counterbalancer requires a blower assembly line to execute a squeezing process which incurs a substantial cost. The use of the generally rectangular rigid counterbalancer referred to above has its own problem in that, because of the shape thereof, not only is an accurate positioning of the counterbalancer on the surface of the blower blade difficult, but care is also required to keep the blade assembly still until after the bonding material cures completely.
With respect to the clip-like counterbalancer, the two-point contact system at which the counterbalancer contacts the blower blade at two points is unable to provide a sufficient retaining force with which the counterbalancer can be firmly mounted on the blower blade and, therefore, this clip-like counterbalancer is apt to be displaced on the blower blade during use of the blade assembly.
While the various types of counterbalancers have their own problems discussed above, an additional problem common to all of these types lies in that, since the counterbalancer has been designed and manufactured with no regard paid to the resistance to the flow of air, the blower blade assembly tends to exhibit unfavorable operating characteristics accompanied by generation of noises and a reduction in air capacity.